Two new estrogen binding systems have been described by us in the pancreas of animals and the human. We have found an estrogen receptor protein in the acinar cells of the pancreas, similar to the cytoplasmic receptors described in other tissues (uterus, breast), and another protein associated with the cytoplasmic microsomes. This latter estrogen binding protein (EBP) has a high capacity for binding estradiol-17 beta (E2). The major aims of the proposed research are: 1. To further characterize specific estrogen receptors in the pancreas of the human and animals. Much attention will be payed to the high capacity EBP associated with the microsomes. 2. An evaluation of the concentration of these estrogen binding proteins in normal and cancerous tissues of the pancreas. 3. To establish certain biochemical and physiologic effects of estrogens in the pancreas. This will involve the determination of the effects on pancreatic secretion and the concentration of certain substances in the pancreas and its secretion (e.g., the enzymes trypsin, amylase, lipase, DNAse, RNAse and the levels of electrolytes including zinc). 4. To follow positive results obtained under 3. by attempts to determine the role played by estrogen-protein complexes in the synthesis of specific pancreatic substances, particularly proteins, i.e., amylase, trypsin, etc. as reflected by the synthetic ability of microsomes in vitro. 5. Application of the results to the development of possible chemotherapeutic agents based on the localization of E2 in the pancreas, similar to that of Estracyt (E2 plus a nitrogen mustard) in cancer of the prostate.